Problem: $\dfrac{5}{3} - \dfrac{4}{5} = {?}$
Explanation: $ = {\dfrac{5 \times 5}{3 \times 5}} - {\dfrac{4 \times 3}{5 \times 3}} $ $ = {\dfrac{25}{15}} - {\dfrac{12}{15}} $ $ = \dfrac{{25} - {12}}{15} $ $ = \dfrac{13}{15}$